Improvements in the js code

[python2and3developer]

I made these improvements:

• Inside the function forward. The event handler for mouseover is only attached if $this.opts.pauseonhover is true. Before the handler is attached anyway and the condition was checked inside the handler.

          if ($this.opts.pauseonhover) {
            $this.mouseover(function () {
                clearTimeout(t);
            });
          }

• The block of the if condition:

if (! $this.data( 'tabslet-init' ) ) {
...
}

is very big.
The function returns early if the tabselt-init data attribute was set.

if ( $this.data( 'tabslet-init' ) ) return;